Rough material separation or scalping is a concept whereby a material, usually a coarse material such as coal or the like, is quickly separated into two or more groups wherein precise sizing is not required. Thus, vibrating screens having a precise mesh are not normally required for such operations. Normally in the past, stationary heavy iron rails positioned in a grate-like fashion have been utilized for such applications. Or, alternatively, the material is passed over a maze of rigid bars with the openings between the bars becoming wider near the discharge end of the machine. However, neither type lend themselves to the efficient separation necessary even for the scalping operation particularly in that the material will tend to stratify thereon with some of the material never coming in contact with the separating bars or rails. In addition, these types of prior art devices are not easily adjustable for different sizing applications.